package com.godyao;

import org.junit.Test;

import java.util.concurrent.ConcurrentHashMap;

public class A {
//    private final String a;
//
//    public A(String b) {
//        a = b;
//    }

    @Test
    public void aTest() {
        ConcurrentHashMap<String, Object> objectObjectConcurrentHashMap = new ConcurrentHashMap<>();
        objectObjectConcurrentHashMap.put("a", new Object());
        Object a = objectObjectConcurrentHashMap.get("a");
        System.out.println(a);
    }
}
